@maincolor: red;
.content {
  width: 200px;
  height: 200px;
  .content_wrapper {
    height: 100px;
    color: red;
    padding: 50px / 2;
    margin: (100px / 2);
    background-color: @maincolor;
    //响应式布局,左侧一个菜单栏,宽度自适应根据屏幕30%
    //200px 父容器
    //200px * 0.3 = 60px ,最终宽度为100px;preset-env会进行语法降级
    width: clamp(100px, 30%, 200px);
    user-select: none;
  }
}
